COSTIGAN – Orange plastic fencing cordons off the site of a gasoline spill on the banks of the Penobscot River here.

Yellow caution tape is tied from tree to tree along the river’s edge in order to keep walkers off the polluted ground.

Two gigantic, red filtration cylinders used to remove gasoline from the soil stand in a roped-off area in the parking lot near Burr’s General Store, where a group of about 40 conservationists gathered Saturday as part of the fall conference sponsored by Maine Rivers, a statewide alliance devoted to the restoration and protection of river systems.

While the riverside scene in Costigan might seem grim, in some ways it’s a success story, said organizers of the weekend conference on Indian Island.

“Pay close attention to the little things because they can turn out to be very important,” Dan Kusnierz, manager of the Penobscot Nation’s water resource program, advised the group after recounting the fortunate – and somewhat accidental – discovery of the leak during Labor Day weekend.

A pair of canoeists from Indian Island thought they smelled gasoline during a brief stop at the store, behind which they noticed a sheen on the water, Kusnierz said. The odor was reported to the Department of Environmental Protection, which investigated and initially found nothing, he said.

Upon further scrutiny, officials detected a small but apparently long-term leak in the piping to the store’s gasoline pumps, which were immediately shut down and remained closed this weekend.

“Who knows how long it could have gone on, if we didn’t notice it?” said Kusnierz, noting that the tribe’s extensive water quality testing program does not detect gasoline.

Natural Resources Council of Maine representative Betsy Ham said it’s that kind of close relationship with the river that provided the focus of the two-day conference, which brought about 130 people to the Sockalexis Center.

“It’s important for all of us to make that strong connection,” said Ham, who stressed the need to recognize both biological and spiritual connections to the state’s rivers.

“At the end of our prayers we ask for the protection of all our relatives … and those include the ants, the birds and the waters,” Ham said, recounting a morning talk by Penobscot Chief Barry Dana. “When we say that, we’re making a pledge to honor and respect those relatives.”

Ham said that there is still “plenty of frustration” with attempts to improve water quality in the state’s rivers, many of which have had toxic chemicals dumped into them for generations. While much remains to be done, Ham said, some of those rivers have gained ground in the past year, including the Kennebec River, which she said is recovering after the 1999 removal of the Edwards Dam.

The health of Maine’s 3,700 miles of rivers and 28,000 miles of streams was an overlying theme of the conference this weekend, with groups discussing subjects including fund raising, enforcement of environmental law, building community action groups and education.